The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Referring now to FIG. 1, a functional block diagram of an engine system according to the prior art is presented. An internal combustion engine 100 is controlled by a control module 104. The control module 104 also controls a transmission 108. The control module 104 receives driver input from an accelerator input module 110 and from a transmission input module 112.
The accelerator input module 110 may include an accelerator pedal and pedal position sensors. The transmission input module 112 may include a gearshift lever, gearshift paddles, and/or gearshift buttons. Based on the driver input, the control module 104 controls a throttle valve 116. The throttle valve 116 regulates air intake into an intake manifold 118 of the engine 100. The position of the throttle valve 116 may be measured by a throttle position sensor 120.
The amount of air flowing into the intake manifold 118 may be measured by a mass air flow (MAF) sensor 122. The pressure inside the intake manifold 118 may be measured by a manifold absolute pressure (MAP) sensor 124. Air from the intake manifold 118 is combined with fuel to create an air-fuel mixture in one or more cylinders 126. For example only, eight cylinders 126 are shown in FIG. 1, although more or fewer cylinders may be present.
Combusting the air-fuel mixture in the cylinders 126 produces torque to turn a crankshaft (not shown). The crankshaft is coupled to the transmission 108 via a torque transmitting device 130, such as a torque converter or a clutch. The speed of the crankshaft may be measured by an RPM (revolutions per minute) sensor 132. When maximum torque is not required, one or more of the cylinders 126 may be disabled to improve fuel economy. For example, the cylinders 126 having diagonal hash marks, such as the cylinder 126-1, may be disabled.
The control module 104 operates a lifter oil manifold assembly (LOMA) 134 to disable selected ones of the cylinders 126. Valves (not shown) of each of the cylinders 126 may be actuated by rocker arms via pushrods driven off a camshaft. Lifters interface between the camshafts and pushrods. Alternatively, lifters may directly interface between the camshafts and valves in an overhead cam engine configuration. There is a hydraulically switchable lost motion portion of the lifters. In order to disable the selected cylinders, the LOMA 134 hydraulically decouples the lifters using solenoid-actuated valves. The intake and/or exhaust valves of the selected cylinders will then remain closed, disabling those cylinders.